Are you sure they are 137GB? We have 144GB drives in our system and OnTap reports them as 133GB. The discrepancy is that drive manufacturers report capacity in base 10 rather than binary. Therefore, drive manufacturers report 144,000,000,000 as 144GB when in reality it is 144,000,000,000/1024^3 == 134GB. In the "real" world giga = 1 billion in the computing world gig = 1024^3 or 1,073,741,824 bytes. If you use 134 instead of 137 for your calculations you will come out pretty close to what the filer is showing you for results. Also, I don't think it is x .9 THEN x .95. If you use 1=34GB drives and x .85 (10% + 5%) you will only be off by 8GB.

-----Original Message----- From: owner-toasters@mathworks.com [mailto:Jochen.Willeke@wincor-nixdorf.com] Sent: Friday, February 24, 2006 7:04 AM To: toasters@mathworks.com Subject: Aggregate size question

Hi everyboby,

i have a little question about aggregate sizing. I have a aggregate called aggr1 consisting of 24 disks â 137 GB hosted on a FAS920c running Ontap 7.0.1R1.

As i have 2 raidgroups 4 disks are parity. I took the 20 left disks and calculated the following:

20 (disks) x 137 GB (size) x 0,90 (10% WAFL) x 0,95 (5% Aggr Snapshot) = 2342,7 GB

When i perform a 'df -Ahr' i only see this:

df -Ahr Aggregate total used avail reserved aggr1 2270GB 1924GB 346GB 0GB aggr1/.snapshot 119GB 34GB 84GB 0GB

So i have a difference of about 70 GB between my result and the total which Ontap shows me. Ok, 70 GB won't make the world turn faster :-) but i would like to understand why i am missing 70 GB.

Thanks in advance

Jochen